Hope somone can Help,when im putting SE drums down on the piano roll i cannot hear some of the beats when i play it back.?

Welcome to the forum.
What are "SE drums"?
Which version of SONAR LE do you have?
What operating system are you running and is it 32-bit or 64-bit?
What synth are you using to hear the MIDI?
What sound card or audio interface are you using?
 

Hey sorry and thanks for the reply Gregy only been at this a week.
The drums are SI drums.
The version is Sonar LE 8.5.1.
I using windows i think its only 16 bit.
the interface is a UA-25 EX.
Hope that helps.
 

The most common cause of randomly skipped MIDI-notes is too small buffer in
"MIDI buffers...prepare using xx ms buffers". Double the buffer size, that might help. 

It's also possible that you're inputting notes that don't have samples loaded for those notes.
When you click on the drum name on the left (or piano key), do those notes make noise? If no, there is no sample for that note. If yes, then you may have to tweak some settings like Kalle wrote.
 

Hi guys I've been away for a week at work so no time for Question's.
So how do I make my buffer bigger.?

Go to the Options dialogue.

Thank you Kalle & Gregy Im on my way.